Vitamin B ruled out as mental booster

Alzheimer's study conducted by UCSD

HOPES AND FRUSTRATIONS
The search for ways to treat Alzheimer's disease has been filled with high expectations and disappointing results.

Some methods that haven't worked:

A clinical trial at the University of California San Diego found that high doses of vitamin B did not alter mental decline caused by Alzheimer's.

Cholesterol-lowering statin drugs, including Lipitor, have failed to slow mental and physical deterioration in Alzheimer's patients.

The experimental drug Flurizan didn't help combat Alzheimer's even though it reduced the amount of beta-amyloid proteins, which cause plaque buildup in the brain.

Some methods being tested:

Rember has shown promise in early-stage clinical trials. The drug is supposed to prevent formation of destructive “tangles” in the brains of Alzheimer's patients that are formed by a protein called tau.

Researchers are studying whether Dimebon, which originated 25 years ago as an antihistamine in Russia, could create or restore brain-cell connections damaged by Alzheimer's disease.

SAN DIEGO

New research by UCSD scientists has debunked another possible treatment for Alzheimer's, a progressive and incurable disease that causes loss of memory and other brain functions.

Alzheimer's patients who took high doses of vitamin B supplements in the university's clinical trial suffered the same level of mental decline over 18 months as those who took a placebo, according to the study, which is published today in The Journal of the American Medical Association.

It's the latest in a string of failed weapons against the disease, which continues to confound neurologists and drug companies after decades of intensive research.

Despite finding harmful plaque, protein “tangles” and elevated levels of a certain amino acid in the brains of Alzheimer's sufferers, scientists still don't know whether those conditions are causes or effects of the disease.

The latest study “reaffirms how complicated Alzheimer's is,” said Roberto Velasquez of the San Diego and Imperial counties chapter of the Alzheimer's Association. “There are a number of theories as to the cause of the disease, but nobody really knows for sure,” he added.

Four drugs have been approved in the United States to treat Alzheimer's disease. All of them stimulate undamaged brain cells to improve memory power, but their beneficial effect usually fades within 18 months.

Researchers had considered vitamin B as a promising and affordable therapy for the disease, which affects 5 million Americans. The vitamin is able to lower levels of homocysteine, an amino acid found in the brain.

“When vitamin B levels are low, homocysteine goes up because it can't be properly metabolized,” said Dr. Paul Aisen, director of the Alzheimer's Disease Research Center at the University of California San Diego. He served as lead investigator for the federally funded study.

Some Alzheimer's patients have been taking over-the-counter and prescription doses of vitamin B for years. The vitamin also is found naturally in many foods, such as potatoes, bananas and tuna.

The UCSD study marked the first time vitamin B was tested on a large population over a period long enough to produce convincing results.

Researchers randomly assigned 409 Alzheimer's patients to two groups. Sixty percent of the participants received high-dose supplements containing vitamin B6, vitamin B12 and folic acid, another form of vitamin B. The rest were given a placebo.